Heating, ventilation, and air conditioning (HVAC[1]) is the technology of indoor and vehicular environmental comfort. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics and heat transfer. "Refrigeration" is sometimes added to the field's abbreviation, as HVAC&R or HVACR or "ventilation" is dropped, as in HACR (as in the designation of HACR-rated circuit breakers).

In a chilled water system, liquid water is pumped throughout the building to “chilled water coils”. Since the liquid water needs to be at a cold temperature, a “cooling plant” is required. The plant is typically referred to as a chiller plant. Vapor compression equipment in the plant, similar to that described in “How does my AC work”, cool water to a cold temperature and pump the cold water to air-to-water heat exchangers where needed.


As a Leesburg and Ashburn AC repair company, we offer emergency and routine AC repair services to the residents and commercial companies in Leesburg and Ashburn, Virginia. We're professional, prompt and punctual. Please call us immediately for your your repair needs. Operators are standing by to take your call. We also encourage you to read our reviews on our Google page.
Heil HVAC is another one of the best air conditioner brands that doesn’t get as much love as they should. This AC brand’s tech allows different heating and cooling components  send information and synchronize performance, becoming more energy efficient and reliable overall. Heil AC products can achieve up to a 97% efficiency rating and SEER figures of 19. They also come with comprehensive 10 year warranties.
Whenever you need any installation, repair, or maintenance for your heating system, call Baker Brothers. We are committed to providing the best customer service and getting your issues solved quickly and efficiently. We service all major make and models of electric and gas heating system in your home. Baker Brothers employs only the best heater/furnace service professionals that are ready to get your home comfortable for you during those cold days and nights.
By completing this annual service of your air conditioning system, you will be helping to prolong its life, improve its efficiency and ensure that it provides cool comfort throughout the summer ahead. You can get all of this with our Baker Brothers Family Plan Membership. This plan offers customers an annual inspection that helps detect many problems before they become significant. You also get other benefits such as priority scheduling and up to 15% off parts and labor.
Mitsubishi Electric is a world leader in air conditioning systems for residential, commercial and industrial use. Challenged to create air conditioning systems that provide exemplary performance in the wide-ranging climatic conditions found throughout Japan, our engineers develop amazingly sophisticated yet durable units and systems capable of constant use under virtually any natural climatic condition on earth.
Extensive training – Over the years, we have had to learn continually and update our skills to stay top-of-the-line. We continue to offer state-of-the-art products today with the service skills to match. We offer 800 hours of training classes to our technicians every year. They also have access to factory resource personnel and engineers for consultation.

You can adjust for seasons: During the summer, you can have the air conditioner stay off during the cooler morning hours and start cooling the house as everyone gets up and starts moving around. During the winter, you can have your heater stay off while you are away at work and turn on about a half hour or so before you get home so that you are coming home to a nice, warm house.
Non fluorochemical refrigerants, such as ammonia (R717), carbon dioxide (R744) and hydrocarbons such as propane (R290) or isobutene (R600a). These products exist naturally in the environment. Alternative to fluorochemical refrigerants, often used due to their low direct GWP and ODP potential. (However it should be noted that commercial production of natural refrigerants is normally via man-made synthesis).
The liquid refrigerant is returned to another heat exchanger where it is allowed to evaporate, hence the heat exchanger is often called an evaporating coil or evaporator. As the liquid refrigerant evaporates it absorbs energy (heat) from the inside air, returns to the compressor, and repeats the cycle. In the process, heat is absorbed from indoors and transferred outdoors, resulting in cooling of the building.

Air conditioning is common in the US, with 88% of new single-family homes constructed in 2011 including air conditioning, ranging from 99% in the South to 62% in the West.[50] In Canada, air conditioning use varies by province. In 2013, 55% of Canadian households reported having an air conditioner, with high use in Manitoba (80%), Ontario (78%), Saskatchewan (67%), and Quebec (54%) and lower use in Prince Edward Island (23%), British Columbia (21%), and Newfoundland and Labrador (9%).[51] In Europe, home air conditioning is generally less common. Southern European countries such as Greece have seen a wide proliferation of home air-conditioning units in recent years.[52] In another southern European country, Malta, it is estimated that around 55% of households have an air conditioner installed.[53] In India AC sales have dropped by 40%[clarification needed] due to higher costs and stricter energy efficiency regulations.[54]

A true central air-conditioning system uses ducts to distribute cooled air throughout the house. In a “split system,” the most common design, refrigerant circulates between an indoor coil and a matching—meaning from the same brand—outdoor condenser with compressor (see illustration, below). The refrigerant cools the air, dehumidifying it in the process; a blower circulates air through ducts throughout the house. A thermostat maintains the temperature at the setting you select. A variation is the “heat pump,” a type of system that functions as heater and air conditioner.
Roof-mounted systems have the heating and cooling systems in one cabinet. Sometimes called "gas packs" (if the heater uses natural gas), they typically cost less than a comparable split system. In dry regions, most homes originally had "swamp-coolers" installed. When replacing them with HVAC systems, it's often cheaper to use existing mounts and ducting.
Window unit air conditioners are installed in an open window. The interior air is cooled as a fan blows it over the evaporator. On the exterior the heat drawn from the interior is dissipated into the environment as a second fan blows outside air over the condenser. A large house or building may have several such units, allowing each room to be cooled separately.

You've probably noticed many appliances boasting an Energy Star Certification. What this means is that manufacturer voluntarily built the product to help reduce greenhouse gases and meet non-regulatory guidelines offered by the Environmental Protection Agency. To earn an Energy Star rating, a product or system must be tested by a third party that has been recognized by the EPA for meeting their testing qualifications.
The three major functions of heating, ventilation, and air conditioning are interrelated, especially with the need to provide thermal comfort and acceptable indoor air quality within reasonable installation, operation, and maintenance costs. HVAC systems can be used in both domestic and commercial environments. HVAC systems can provide ventilation, and maintain pressure relationships between spaces. The means of air delivery and removal from spaces is known as room air distribution.[3]
With the split system, the evaporator coil is connected to a remote condenser unit using refrigerant piping between an indoor and outdoor unit instead of ducting air directly from the outdoor unit. Indoor units with directional vents mount onto walls, suspended from ceilings, or fit into the ceiling. Other indoor units mount inside the ceiling cavity, so that short lengths of duct handle air from the indoor unit to vents or diffusers around the rooms.
Our goal is to make you more comfortable in your home. When your furnace, central air conditioner, heat pump or boiler stops working and you need service, call the professionals at BGE HOME. Heating and cooling system breakdowns occur at the most inconvenient times, so rely on our certified, skilled technicians to make the repair quickly and correctly the first time.

If your furnace has a pilot light, look for the flame. Check your owner’s manual or the instructions posted inside the furnace cabinet for step-by-step lighting instructions. Usually this involves first turning the gas valve to Off and waiting a couple of minutes. Then you turn it to Pilot. Next, press and hold it down while you light the flame. Last, wait a minute or so, release it, and then turn it to On.


This is a great option for cooling your home or business without having to deal with the ductwork.  Other systems require ductwork so that the cool air can travel throughout the space.  A ductless mini split air condition doesn’t require ductwork because it has an air conditioner or a heat pump outside that connects to units in the home that handle the cooling being pushed into them from outside.  You can control the temperature of a whole home or just one room by controlling the air handlers in each specific area.  This allows for more control and a more efficient way to control the temperature and cost of operating the ductless mini split air conditioner.

R407C is a zeotropic hydro-fluoro-carbon refrigerant and is a blend of difluoromethane (R32) providing the heat capacity, pentafluoroethane (R125) decreasing flammability and tetrafluoroethane (R134a) to reduce pressure. Difluoromethane serves to, pentafluoroethane andtetrafluoroethane. R407C was developed as a replacement for the ozone depleting R22.


At Sky Heating & Air Conditioning, we understand that HVAC services can really hurt your budget. Many times, you don’t expect to make such large purchases until an emergency arises. We never want you to feel that you cannot afford your comfort and safety. We offer flexible financing options through the Home Project credit card from Wells Fargo, with approved credit. Head over to our financing page to apply, or give us a call for more information!

Who do you call when you have a HVAC related issue? How do you know that you’re making a call to the right team? Much of Cary has come to trust us here at Service Experts Heating & Air Conditioning for all their heating and air conditioning needs. Our qualified technicians know what they’re doing. No matter your problem or question, our team is able to help—no issue is too big or too small in Cary. You can feel comfortable in your decision to call Service Experts and know that you’re working with a team that has your back.
As a family owned and operated full-service HVAC provider in Erie, we recognize the concerns and challenges of keeping your home and family perfectly comfortable without breaking your budget.  At Nerthling's Heating and Air Conditioning, we go above and beyond to eliminate inconvenience, protect your investment, and find solutions you can easily afford.  To better serve your needs, we offer extended regular service hours from 8 to 6 PM Monday through Saturday, available throughout Erie County, including Millcreek, PA, Erie, PA & Fairview, PA.  In emergency situations, we are always available, twenty-four hours a day, seven days a week.  Know that when you call Nerthling's Heating and Air Conditioning, we are 100% committed to your satisfaction.  We treat your home like it’s our own.
An air conditioning system, or a standalone air conditioner, provides cooling and humidity control for all or part of a building. Air conditioned buildings often have sealed windows, because open windows would work against the system intended to maintain constant indoor air conditions. Outside, fresh air is generally drawn into the system by a vent into the indoor heat exchanger section, creating positive air pressure. The percentage of return air made up of fresh air can usually be manipulated by adjusting the opening of this vent. Typical fresh air intake is about 10%.
A specialized air conditioner that is used only for dehumidifying is called a dehumidifier. It also uses a refrigeration cycle, but differs from a standard air conditioner in that both the evaporator and the condenser are placed in the same air path. A standard air conditioner transfers heat energy out of the room because its condenser coil releases heat outside. However, since all components of the dehumidifier are in the same room, no heat energy is removed. Instead, the electric power consumed by the dehumidifier remains in the room as heat, so the room is actually heated, just as by an electric heater that draws the same amount of power.
Our goal is to make you more comfortable in your home. When your furnace, central air conditioner, heat pump or boiler stops working and you need service, call the professionals at BGE HOME. Heating and cooling system breakdowns occur at the most inconvenient times, so rely on our certified, skilled technicians to make the repair quickly and correctly the first time.
"Warren at Lighten Up came in on time and as scheduled. Loved working with him. He provided new lighting for our kitchen remodel and did a great job. He still needs to come back and hook everything up. Also Seth came in and did some plumbing work and repair that we did not even know needed repair. I highly recommend this company and look forward to working with them in the future"
Getting one of the best air conditioner brands is important whether you’re replacing an old HVAC system, or having the first AC unit system put in your brand new home, but it’s not everything. The best Trane, Ruud, or American Standard HVAC system won’t perform any better than a no-name bargain air conditioner system if it’s not installed properly by a quality HVAC contractor. It’s important to find an HVAC installation professional with high ratings and expert knowledge within the field so that your top brand can perform at optimal efficiency.
Even if your air conditioning unit is still working, depending on the type of system in your home today, you could recoup your investment in a new system in as little as three years. However, that doesn't mean that your system needs to be replaced. Furnaces, air conditioners, and other heating and cooling systems have made tremendous gains in efficiency over the past five years, so if you have an older unit, it is worth taking a look at whether or not a repair is the best investment.
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